Winding/hoisting ropes extended life creep effect 1

[shorion]

Hi, can anyone point me in the direction of any information on the extended use of winding/hoisting ropes.

In particular the creep experienced as the rope gets older due to the load (permanent deformation)

Any books or standards or research articles where some information on this topic might be found.

I've done a bit on elongation under load but am yet to see something on creep due to extended use over time.

Regards

 

[Compositepro]

A Google search for "long term creep in ropes" comes-up with plenty of information.

 

[shorion]

Sorry, I should have mentioned this is for steel wire strands 35x7's etc not the synthetics and polymers in winding and hoisting applications.

 

[dhengr]

Shorion:
You would probably do well to talk with some of the engineering people at your wire rope suppliers, or people looking for your business. Don’t settle for the b.s. you get from the sales guys, get with their real engineering people. You can get elastic stretching from loading, wire by wire; and you will certainly get mechanical/relaxation stretching as the wires in the cable settle/adjust into a tighter bundle. Off hand, I’m not real sure about much creep if the wire rope is not stressed to a very high level continuously, or working at a very high temp. And, you probably shouldn’t be working the wire rope at those stress or temp. levels. Those wire rope engineers should have some info. or knowledge on this. You will extend the life and load cap’y. more effectively by running your wire rope over larger dia. sheaves, thus reducing bending stresses.

 

[shorion]

Excellent, Thanks Dhengr, this was exactly the path it looks like I'm going down. The bedding down was less than the manufactures limits in their guides but I'm trying to contact their engineers now. Just to be safe.



Regards

 

[miningman]

You should probably also get intimately familiar with the local regulatory requirements regarding testing of such ropes. You may well find that you have no choice but to change the ropes out say every two years, or even sooner if testing at say six months intervals shows deterioration beyond a certain well defined limit.